Elementals are a type of creature that hail from the 
Elemental planes. They are creatures that embody a single elemental plane.
“Creatures native to the Elemental Planes. They range from simple masses of a specific element to beings infused with elemental energy.„
Characteristics
Elementals come in a wide variety of forms and sizes depending on their element. They don't typically have features typical of other creatures, as they are generally made of the element's plane they come from. They are often, but not always, resistant or immune to the damage type associated with their element.
Types of elementals
Azer
“Master craftsmen and expert miners made from bronze and fire.„
Azer are dwarf-like creatures with bronze skin that burns so hot that their weapons and bodies can burn nearby creatures.
Mephit
“Capricious, vulgar, and rarely endearing - except to their masters. Mephits are curious, impish creatures from the Elemental Planes.„
Mephits are imp-like creatures that enjoy being tricksters.
Mephits in Baldur's Gate 3
Mud Elemental
“These sludgy, muculent elementals come from a Plane intersecting Elemental realms of Water and Earth.„
Mud elementals are strong, humanoid shaped masses of mud.
Lava Elemental
“These superheated sacks of molten slag come from a Plane intersecting Elemental realms of Earth and Fire.„
Lava elementals are similar in appearance to earth elementals except they are made of lava.
Other
Related items
Voss' Silver Sword - +1d4 bonus to attack rolls and damage against elementals
Related spells and abilities
- if successful, banishes an elemental back to their plane of existence.
- won't grant advantage against injured elementals
- if successful, takes control of enemy elemental
- elementals have disadvantage against the target
- won't apply 
to elementals